The suit, which was filed in the Alameda County Superior Court Friday, states BART has a legal obligation to protect its passengers from assault, the East Bay Times reported April 12.

“This lawsuit is part of Nia Wilson’s family’s commitment to hold BART accountable for cleaning up its system. No one else should have to suffer because of BART’s failure to protect its riders from harm,” attorneys Jonathan Davis and Robert Arns from San Francisco-based Arns Law Firm said in a statement Friday.

Crowell, who was a serial fare evader, attacked Wilson and her older sister, who had been coming back from a birthday celebration for the now-deceased victim’s late boyfriend. Police said Crowell “struck very rapidly” as the siblings exited a train at MacArthur station.

Later, detectives discovered a knife at a construction site close to the station that was used in the attack.

Wilson was slashed across the neck and bled out on the platform. Her sister, Letifah Wilson, was stabbed in the neck, but she survived.

The lawsuit says Crowell should never have been able to get into the transit station and he should have been prohibited from entering at the turnstiles. The filing, which was made after the family filed a complaint with BART that was not given a response, states that Nia Wilson’s death was preventable since there is a lack of proper safety measures at the turnstiles to stop criminals from entering transit system.

The claim states the attack is not a “horrific anomaly” but it occurred as part of “a serious and endemic public safety problem.”

In order to solve this problem, the filing proposes BART enact policies to prevent crime. It also wants the establishment of the Nia Wilson Crime Statistics Notice, which would alert the public to accurate and current criminal activity at each station.

Additionally, the suit says the Wilson sister’s father, Ansar El Muhammad, arrived at the station to discover Nia Wilson covered in a blanket in a pool of blood and her sister cloaked in blood. The father, as well as other family members, say they’ve suffered serious emotional distress as a result of the incident. The family is also seeking monetary damages.

BART chief spokesperson Alicia Trost told the East Bay Times that the transit agency is unable to speak on pending cases.